| written 9.5 years ago by | • modified 9.5 years ago |

$x^2+y^2-2x = 0$ . is an equation of circle
Here $2g=-2 , 2f=0 $
$$\therefore g=-1\space f=0$$
$\therefore $ center is at $(-g,-f)$ i.e. $(1,0)$ and radius is $\sqrt{g^2+f^2-c}=\sqrt{12}=1$
$$Y=2x$$
It is an equation of line passing from origin. As shown in diagram
$Y^2 = 2x$ is parabola.
The point of intersection of line and parabola is calculated as: $Y^2 = 2x$ and $y = x$
$$\therefore x^2 = 2x $$
$$\therefore x^2-2x=0$$
$$\therefore x(x-2) = 0$$
$$\therefore \space x = 0 or \space x=2 $$
When $x=0 ,y=0 $
When $x=2 , y=2 $
$\therefore$ The vertical strip will slide from 0 to 2 on x-axis.
But the region is divided into two parts as the inner lower limit is different.
Intersection of line and circle
$$X^2+y^2-2x=0$$ and $$y=x$$
$$\therefore x^2+x^2-2x=0 $$
$$\therefore 2x^2-2x=0$$
$$\therefore 2x(x-1)=0$$
$$\therefore \space x=0 or \space x=1 $$
When $x=0 ,y=0$
$$ X=1 , y=1$$
Region (I)
1) Outer limit $x=0 to x=1$
2) Inner limit y
a) Upper limit is equation of parabola i.e. $y^2 = 2x $
$$\therefore y = =\sqrt {2x}$$
b) lower limit is equation of circle i.e.
$$x^2 + y^2 – 2x = 0 $$
$$\therefore y^2 = 2x-x^2$$
$$\therefore y= \sqrt{2x-x^2}$$
Region (II)
1) Outer limit $x=1$ to z
2) Inner limit y.
a) Upper limit is equation of parabola i.e. $y =\sqrt{2x}$
b) Lower limit is equation of line $ y=x $
$\therefore I=\int\limits^1_{x=0}\int\limits_{y=\sqrt{2x-x^2}}^{\sqrt{2x}}xy\space dydx +\int \limits^2_{x=1}\int^{\sqrt {2x}}_{y=x} xy\space dydx\\ =\int\limits_0^1x\Bigg[\dfrac {y^2}2\Bigg]^{\sqrt{2x}}\dfrac {dx}{\sqrt{2x-x^2}}+\int\limits_1^2x\Bigg[\dfrac {y^2}2\Bigg]^{\sqrt{2x}}_xdx\\ =\int\limits_0^1x\Bigg[\dfrac {2x}2-\dfrac {(2x-x^2)}2\Bigg]dx+\int\limits^2_1x\Bigg[\Bigg(\dfrac {2x}2\Bigg)-\dfrac {x^2}2\Bigg]dx\\ =\int\limits_0^1\Bigg(x^2-x^2+\dfrac {x^3}3dx+\int\limits_1^2\Bigg(x^2-\dfrac {x^3}2\Bigg)dx\\ =\Bigg[\dfrac {x^4}8\Bigg]^1_0+\Bigg[\dfrac {x^3}3-\dfrac {x^4}8\Bigg]^2_1\\ =\dfrac 18+\Bigg[\dfrac 83-\dfrac 13-\dfrac {16}8+\dfrac 18\Bigg]\\ =\dfrac 7{12}$

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